Delta letters of rec
 

Is there a limit as to how many letters can be attached to your app?

Nope, seem guys with 25. Just make sure they are from people that have nothing to gain by you getting hired. For example guys with apps in as well.

DAL internal recs are good, as are LCA's, CP, Director of Ops. Stay away from your priest, sister, flight attendant neighbor unless it is really good etc.

Also make sure your References are Golden as well. I recommend DAL references.